Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Oregon scientists offer new insights on controlling nanoparticle stability: New findings could enhance stabilizing or destabilizing nanoparticles, depending on their uses

University of Oregon chemistry professor James Hutchison has uncovered important information about the stability of nanoparticles that could help drive more precise preparation of particles or precursors for thin films.

Credit: University of Oregon
University of Oregon chemistry professor James Hutchison has uncovered important information about the stability of nanoparticles that could help drive more precise preparation of particles or precursors for thin films.

Credit: University of Oregon

Abstract:
University of Oregon chemists studying the structure of ligand-stabilized gold nanoparticles have captured fundamental new insights about their stability. The information, they say, could help to maintain a desired, integral property in nanoparticles used in electronic devices, where stability is important, or to design them so they readily condense into thin films for such things as inks or catalysts in electronic or solar devices.

Oregon scientists offer new insights on controlling nanoparticle stability: New findings could enhance stabilizing or destabilizing nanoparticles, depending on their uses

Eugene, OR | Posted on December 9th, 2013

In a project — detailed in the Nov. 27 issue of the Journal of Physical Chemistry C — doctoral student Beverly L. Smith and James E. Hutchison, who holds the Lokey-Harrington Chair in Chemistry at the UO, analyzed how nanoparticle size and molecules on their surfaces, called ligands, influence structural integrity under rising temperatures.

They focused on nanoparticles less than two nanometers in diameter — the smallest studied to date — to better understand structural stability of these tiny particles being engineered for use in electronics, medicine and other materials. Whether a nanoparticle needs to remain stable or condense depends on how they are being used. Those used as catalysts in industrial chemical processing or quantum dots for lighting need to remain intact; if they are precursors for coatings in solar devices or for printing ink, nanoparticles need to be unstable so they sinter and condense into a thin mass.

For their experiments, Smith and Hutchison produced gold nanoparticles in four well-controlled sizes, ranging from 0.9 nanometers to 1.5 nanometers, and analyzed ligand loss and sintering with thermogravimetric analysis and differential scanning calorimetry, and examined the resulting films by scanning electron microscopy and X-ray photoelectron spectroscopy. As the nanoparticles were heated at 5 degrees Celsius per minute, from room temperature to 600 degrees Celsius, the nanoparticles began to transform near 150 degrees Celsius.

The researchers found that smaller nanoparticles have better structural integrity than larger-sized particles that have been tested. In other words, Hutchison said, they are less likely to lose their ligands and bind together. "If you have unstable particles, then the property you want is fleeting," he said. "Either the light emission degrades over time and you're done, or the metal becomes inactive and you're done. In that case, you want to preserve the function and keep the particles from aggregating."The opposite is desired for Hutchison and others working in the National Science Foundation-funded Center for Sustainable Materials Chemistry, a multi-universities collaboration led by the UO and Oregon State University. Researchers there are synthesizing nanoparticles as precursors for thin films.

"We want solution precursors that can lead to inorganic thin films for use in electronics and solar industries," said Hutchison, who also is a member of the UO Materials Science Institute.

"In this case, we want to know how to keep our nanoparticles or other precursors stable enough in solution so that we can work with them, using just a tiny amount of additional energy to make them unstable so that they condense into a film -- where the property that you want comes from the extended solid that is generated, not from the nanoparticles themselves."

The research, Hutchison said, identified weak sites on nanoparticles where ligands might pop off. If only a small amount do so, he said, separate nanoparticles are more likely to come together and begin the sintering process to create thin films.

"That's a really stabilizing effect that, in turn, kicks out all these ligands on the outside," he said. "The surface area decreases quickly and the particles get bigger, but now all the extra ligands gets excluded into the film and then, over time, the ligands vaporize and go away."

The coming apart, however, is a "catastrophic failure" if protecting against sintering is the goal. It may be possible to use the findings, he said, to explore ways to strengthen nanoparticles, such as developing ligands that bind in at least two sites or avoiding volatile ligands.

The process, as studied, produced porous gold films. "A next step might be to study how to manipulate the process to get a more dense film if that is desired," Hutchison said. Understanding how nanoparticles respond to certain conditions, such as changing temperatures, he added, may help researchers reduce waste in the manufacturing process.

"Researchers at the University of Oregon are re-engineering the science, manufacturing and business processes behind critical products," said Kimberly Andrews Espy, vice president for research and innovation and dean of the UO Graduate School. "This research analyzing the structural stability of nanoparticles by Dr. Hutchison and his team has the potential to improve the engineering of electronics, medicine and other materials, helping to foster a sustainable future for our planet and its people."

Smith, the paper's lead author, received a master's degree in chemistry in 2009 from the UO. She now is a doctoral student in Hutchison's lab. During the initial stages of the research, she was supported by the NSF's Integrative Graduate Education and Research Traineeship (IGERT) program. Funding from the Air Force Research Laboratory (grant No. FA8650-05-1-5041) to Hutchison also supported the research.

Hutchison also is a member of both the Oregon Nanoscience and Microtechnologies Institute (ONAMI) and Oregon BEST (Oregon Built Environment & Sustainable Technologies Center), which are state signature research initiatives.

####

About University of Oregon
The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.

Follow UO Science on Facebook: http://www.facebook.com/UniversityOfOregonScience

UO Science on Twitter: http://twitter.com/UO_Research

More UO Science/Research News: http://uoresearch.uoregon.edu

For more information, please click here

Contacts:
Jim Barlow

541-346-3481

Source:
James Hutchison
professor
Department of Chemistry and Biochemistry
541-346-4228

Copyright © University of Oregon

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Thin films

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Even geckos can lose their grip July 9th, 2014

Shrinky Dinks close the gap for nanowires July 1st, 2014

Micro-manufacturing breakthrough is wired for sound June 24th, 2014

Chip Technology

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Nanometrics Announces Upcoming Investor Events July 22nd, 2014

Penn Study: Understanding Graphene’s Electrical Properties on an Atomic Level July 22nd, 2014

Discoveries

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

UCF Nanotech Spinout Developing Revolutionary Battery Technology: Power the Next Generation of Electronics with Carbon July 23rd, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Announcements

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

A*STAR and industry form S$200M semiconductor R&D July 25th, 2014

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Scientists Test Nanoparticle "Alarm Clock" to Awaken Immune Systems Put to Sleep by Cancer July 25th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

A Crystal Wedding in the Nanocosmos July 23rd, 2014

Nano-sized Chip "Sniffs Out" Explosives Far Better than Trained Dogs: TAU researcher's groundbreaking sensor detects miniscule concentrations of hazardous materials in the air July 23rd, 2014

Energy

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

3-D nanostructure could benefit nanoelectronics, gas storage: Rice U. researchers predict functional advantages of 3-D boron nitride July 15th, 2014

Nanotechnology that will impact the Security & Defense sectors to be discussed at NanoSD2014 conference July 8th, 2014

Solar/Photovoltaic

Steam from the sun: New spongelike structure converts solar energy into steam July 21st, 2014

Making dreams come true: Making graphene from plastic? July 2nd, 2014

Shrinky Dinks close the gap for nanowires July 1st, 2014

New Study Raises Possibility of Production of P-Type Solar Cells July 1st, 2014

Printing/Lithography/Inkjet/Inks

Martini Tech Inc. becomes the exclusive distributor for Yoshioka Seiko Co. porous chucks for Europe and North America July 20th, 2014

University of Illinois researchers demonstrate novel, tunable nanoantennas July 14th, 2014

Haydale Announces Collaboration Agreement with Swansea University’s Welsh Centre for Printing and Coatings (WCPC) July 12th, 2014

Leti to Present Technological Platforms Targeting Industry’s Needs for the Future at Semicon West Workshop: Presentation at STS Session to Focus on Leti Advanced Lithography Programs for 1x Nodes and on Silicon Photonics at TechXPot June 25th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE